The schedule is somewhat tight for Fedora 33, but Python's annual release cycle was adapted for Fedora, hence we have a better chance of making it in time. In the future, it is expected that Python will be upgraded on a similar schedule in every odd-numbered Fedora release.

Note that upstream's "release candidates" are frozen except for blocker bugs. Since we can and will backport blocker fixes between Fedora and upstream, we essentially treat the Release Candidate as the final release.

Reintroduce python3.8 from Fedora 31. Update it to have all fixes and enhancements from python3 in Fedora 32 (or 33 before this change)

Other developers: Maintainers of packages that fail to rebuild during the rebuilds will be asked, using e-mail and bugzilla, to fix or remove their packages from the distribution. If any issues appear, they should be solvable either by communicating with the respective upstreams first and/or applying downstream patches. Also the package maintainers should have a look at: Porting to Python 3.9. The python-maint team will be available to help with fixing issues.

Release engineering: #9046 A targeted rebuild for all python packages will be required, before the mass rebuild.

Upgrade/compatibility impact

All the packages that depend on Python 3 must be rebuilt. User written Python 3 scripts/applications may require a small amount of porting, but mostly Python 3.8 is forward compatible with Python 3.9.

How To Test

Interested testers do not need special hardware. If you have a favorite Python 3 script, module, or application, please test it with Python 3.9 and verify that it still works as you would expect. If the application you are testing does not require any other modules, you can test it using python3.9 even before this change is implemented, in Fedora 30, 31 or 32.

In case your application requires other modules, or if you are testing an rpm package, it is necessary to install the 3.9 version of the python3 rpm. Right now that rpm is available in copr, along with all other python packages that build successfully with python 3.9. See https://copr.fedorainfracloud.org/coprs/g/python/python3.9/ for detailed instructions how to enable Python 3.9 copr for mock.

Once the change is in place, test if you favorite Python apps are working as they were before. File bugs if they don't.

User Experience

Regular distro users shouldn't notice any change in system behavior other than the Python 3 interpreter will be in version 3.8.

Dependencies

Contingency Plan

Contingency mechanism: Do not merge the side tag with rawhide. If the side tag has been merged and issues arise, that will justify a downgrade, then use an epoch tag to revert to 3.8 version (never needed before)